Narrowband communications systems are typically used by public safety agencies, for example, emergency first responder organizations, such as police or fire departments, or public works organizations. Examples of such narrowband systems include a Land Mobile Radio (LMR) system or a Terrestrial Trunked Radio (TETRA) system. Users on these narrowband systems may communicate via mobile or portable user terminals, such as portable narrowband two-way radios, mobile radios, dispatch consoles, or other similar voice communication entities that communicate with one another via wired and/or wireless networks. Public safety organizations may choose these narrowband systems because they provide improved end-to-end voice quality and efficient group communication, use advanced cryptography, enable centralized logging of calls, and/or are associated with lower delay and higher reliability.
A portion of the broadband spectrum, e.g., the 700 MHz spectrum in the United States, has been allocated for public safety use. All public safety agencies and all applications used by these public safety agencies are expected to share this portion of the broadband spectrum. Therefore, in addition to using narrowband systems, public safety agencies may also communicate on cellular broadband systems. An example of such a broadband system is one that operates in accordance with the Long Term Evolution (LTE) signaling standard. Broadband mobile devices used in broadband systems may be, for example, laptops, tablets, personal digital assistants (PDA), smart phones, or other similar broadband mobile devices that communicate with one another via wired and/or wireless networks. In addition to public safety users, user equipment operated by secondary users (for example, utility or government workers) and/or commercial users may also share the portion of the broadband spectrum that has been allocated for public safety use.
Broadband mobile devices may be connected to network resources that are dedicated to certain application services. For example, the broadband mobile devices may also be connected, via a broadband radio access network, to a broadband push-to-talk server or gateway that is dedicated to providing resources for push-to-talk operations. Narrowband mobile or portable user terminals operating on, for example, an LMR system may also be connected to the broadband push-to-talk server or gateway via the LMR system. This allows the broadband mobile devices and the narrowband mobile or portable user terminals to use the same dedicated resources associated with a given application service.
Because of all of the groups of users that are allowed to operate on the portion of the broadband spectrum that has been allocated for public safety, this portion of the broadband spectrum may become congested or coverage to a given broadband network may be lost when, for example, an incident occurs within a geographical area. Incidents may include, for example, a fire, a terrorist attack or another emergency. Consider an example where a large scale attack is carried out within a geographical area. In addition to broadband mobile devices being used by public safety agencies within the vicinity of the incident, user equipment operated by secondary users and/or commercial users are likely to try to access the portion of the broadband spectrum that has been allocated for public safety use. This is likely to lead to congestion on broadband networks operating within that spectrum or loss of access to the broadband networks for some or all of the broadband mobile devices in the geographical area, including those used by public safety agencies. When a broadband mobile device is out of a broadband coverage area or detects that an associated broadband network is congested, the broadband mobile device may either drop all voice and/or data services or provide poor quality of service. For example, if the broadband mobile device is associated with a congested broadband network, information sent from and/or received by the broadband mobile device may have longer delays or poor audio quality.
In addition to the broadband mobile devices operating within the vicinity of an incident, there are likely to be narrowband mobile or portable user terminals operating within the vicinity. Each of the broadband mobile devices and the mobile or portable user terminals (collectively referred to as mobile stations) may include one or more local area network or personal area network transceivers, such as, a Wi-Fi transceiver or a Bluetooth transceiver for device to device communications. Therefore, the mobile stations may further be configured to form an ad-hoc network. An “ad-hoc network” refers to a self-configuring network of geographically-distributed mobile stations connected by wireless links (e.g., radio frequency communication channels). The ad-hoc networks could be built based on a wide band protocol, such as Wi-Fi, Bluetooth, or Zigbee. This enables mobile stations in an ad-hoc network to communicate with each other without the support of an infrastructure-based network. Therefore, even when the broadband mobile devices lose broadband access, these broadband mobile devices can still communicate with other mobile stations in the ad-hoc network. However, these broadband mobile devices may be unable to use the ad-hoc network to access certain network resources and thus be unable to maintain or provide quality of service for certain application services.
Accordingly, there is a need for an improved method and apparatus for enabling a mobile station operating according a first wireless access technology to maintain priority and quality of service for certain application services via a proxy mobile station operating according to a second wireless access technology when a connection between the mobile station and a network operating according to the first wireless access technology is compromised.
Skilled artisans will appreciate that elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions of some of the elements in the figures may be exaggerated relative to other elements to help to improve understanding of embodiments of the present invention.
The apparatus and method components have been represented where appropriate by conventional symbols in the drawings, showing only those specific details that are pertinent to understanding the embodiments of the present invention so as not to obscure the disclosure with details that will be readily apparent to those of ordinary skill in the art having the benefit of the description herein.